With a decrease of dimensions of semiconductor devices, an epitaxial source/drain structure has been widely utilized for fabricating a fin field effect transistor (FinFET). Further, a contact bar (source/drain (S/D) contact layer) is formed over the epitaxial S/D structure to electrically connect the source/drain of the FinFET to an upper layer metal wiring. As the device density increases (i.e., the dimensions of semiconductor device decreases), an electrical separation between the fin structure of one FinFET and the neighboring STI (shallow trench isolation) contact becomes tighter, which may cause a short circuit between the neighboring STI contact and the fin structure.